More than 80% of China's bauxite is A/S5 ~ 8 low-grade diaspore-type bauxite, and it cannot simply use the low energy consumption Bayer process to produce alumina.
Bauxite ore flotation and desilication production of new alumina technology test According to the characteristics of the main mineral content of ore, the less content of silicon-containing gangue mineral floats out, leaving the concentrate in the floatation tank. Compared with positive flotation desilication technology, the advantages are: less floating and more suppression, more reasonable technical principles; flotation of silicon-containing minerals, avoiding collectors, etc. into the concentrate, thereby reducing or avoiding the organic process Bayer process accumulation; easy to take off In addition to the silicon-containing minerals such as pyrophyllite, the rate of crusting on the preheating pipe is reduced; the dewatering performance of the concentrate is good and the moisture content is low.
Industrial trials have developed control of slurry dispersion and desliming techniques; establishment of enhanced trapping of aluminosilicate minerals to selectively inhibit the structure and properties of diaspore flotation agent; revealing major aluminosilicate minerals and cation capture Agent mineral interface interaction flotation behavioral mechanism; development of a small amount of silica-based mineral selective high-efficiency collectors, inhibitors and foaming agents, the establishment of a system of anti-flotation agent desilication process; Controlled decentralized and selective desliming was realized; China's independent intellectual property rights “bauxite selective desliming-cationic reverse flotation desilication†technology was established, and bauxite was first used for reverse flotation desilication-pipeline preheating Dissolution of alumina production process.
The test results show that after the ratio of aluminum to silicon ore 5.88 bauxite, the ratio of aluminum to silicon in the concentrate is 10.12, and the recovery rate of alumina is 82.40%. The concentrate is treated by Bayer process, the pre-silicon removal rate reaches 43%, the dissolution of concentrates, the red mud settlement and compression performance is good, the speed of the pipe crusting is low, and the alumina product quality is good.
The successful development of this new technology has enriched the theory and technology system for the use of low-grade diaspore-type bauxite resources in China, and established a new alumina production method that has reached the international advanced level. The use of this result has expanded the availability of bauxite resources and will help ensure the sustainable development of China's aluminum industry.